(1) Field of the Invention
This invention relates to a webbing retractor which is equipped with an emergency locking mechanism and an automatic locking mechanism - which once the rotation of a take-up spindle in a webbing-releasing direction is locked, continuously locks the rotation of the take-up spindle in the webbing-releasing direction unless this locking is released by a certain operation - and allows to change the automatic locking mechanism from a state ready to actuate to a state not ready to actuate and vice versa by suitably changing the wound state of the webbing on the take-up spindle. The webbing retractor is also provided with a means for preventing locking of the take-up spindle in the webbing-releasing direction when such locking is not needed, even when the emergency locking mechanism is actuated to lock the rotation of the take-up spindle in the webbing-releasing direction.
(2) Description of the Prior Art
Retractors equipped only with emergency locking mechanisms have been known to date, and so are retractors with automatic locking mechanisms alone. Even while webbings are worn, the former retractors still permit a relatively greater degree of freedom to the wearers and the wearers do not feel too much pressure from the webbings. The release of webbing is prevented in the case of the latter retractors and the wearers hence feel relatively large pressures from the webbings.
Baggage or an auxiliary child's seat (hereinafter called "baggage" collectively) is sometimes strapped on a conventional passenger seat by using its associated webbing. In the case of an automatic locking retractor, the release of the webbing is prevented when the baggage is strapped. Therefore, the baggage is firmly held on the seat. However, the release of the webbing is not prevented normally in the case of an emergency locking retractor. There is hence an imminent danger that the webbing is pulled out little by little from the retractor by vibrations and moderate braking and the strapping of the baggage becomes looser while the car is driven.
It is hence desired to develop a retractor having the merits of both an emergency locking retractor and an automatic locking retractor.
When certain predetermined conditions arise, an emergency locking mechanism always takes it as occurrence of an emergency state and hence functions. The emergency locking mechanism may therefore function to lock the release of its associated webbing even when there is actually no emergency state. The emergency locking mechanism may hence function, for example, when the webbing is taken up rapidly into a fully-wound state, the release of the webbing is started from the fully-wound state, or the vehicle body is tilted beyond a certain degree on a slope.
It is therefore desired to solve such inconvenience by a simple structure.